John's Build

[alexM]

John,
Posting this in your thread, looking for some Oratex advice. Correct me if I'm wrong but it looks to me like the toughest place to cover on a Kitfox 5 is the spot where the vertical fin rises from the (flat) aft fuselage. I went digging into your build and it looks like you added a subtle razor back feature. Was it to address this challenge or just because you wanted to do it?

One place the legacy polyester fabrics would make this spot easier is because they can be stretched while it is still dry fabric, where Oratex has no stretch at all until you hit it with heat and pull hard. So far what I've come up with is two ideas, both of which involve a seam across the aft fuselage. I think the easiest would be to cover each side separately, as seen in tape below:
PXL_20220913_211503143.jpg
I'm picturing covering right and left, then covering the flat rear deck with the seam facing aft, then a piece of edge tape up the vertical fin.

My other idea would be to try and cover both sides with one piece, and then complete it as described above:
PXL_20220913_211706390.jpg
In my head I'm imagining sticking it to the curve section at first, and then pulling hard towards the top longerons and then the front and back edges. Possible or crazy? Is a razor back the only way out?

[jrevens]

John,
Posting this in your thread, looking for some Oratex advice. Correct me if I'm wrong but it looks to me like the toughest place to cover on a Kitfox 5 is the spot where the vertical fin rises from the (flat) aft fuselage. I went digging into your build and it looks like you added a subtle razor back feature. Was it to address this challenge or just because you wanted to do it?

One place the legacy polyester fabrics would make this spot easier is because they can be stretched while it is still dry fabric, where Oratex has no stretch at all until you hit it with heat and pull hard. So far what I've come up with is two ideas, both of which involve a seam across the aft fuselage. I think the easiest would be to cover each side separately, as seen in tape below:

I'm picturing covering right and left, then covering the flat rear deck with the seam facing aft, then a piece of edge tape up the vertical fin.

My other idea would be to try and cover both sides with one piece, and then complete it as described above:

In my head I'm imagining sticking it to the curve section at first, and then pulling hard towards the top longerons and then the front and back edges. Possible or crazy? Is a razor back the only way out?

Hi Alex,
Mine is definitely not a great example of how it can be done, but here is what I did, & why. First, you’re spot-on about the difficulty and the razorback making it easier. My kit was done before Kitfox started making the fuselages with the welded on steel razorback tube. It included a piece of curved aluminum tubing that was to be bonded to the structure to modify & extend that front edge of the vertical fin. I modified that curve so that it was a little different than what it was supposed to be at that time, and what it is now on the current fuselages. I shortened it so that I could locate & weld on a mounting plate for my com antenna that is a little further back from the rear edge of the turtleback cover than on the current kits (which now include a mounting plate). I was thinking that I wanted a little more clearance from the antenna when loading/unloading the cargo bay (I had the hinged cover idea in my mind at the time also) So, I did it just like your first proposal, but I added a flat piece of aluminum across the top of the fuselage in that area to give me a good surface to make a fabric overlapping splice, since there was no cross tube where I wanted to do that. I could have done a much better job with the aluminum piece, and it shows & isn’t very attractive under the fabric. The whole job would be easier with the flatter curve of the original current design.